Two-thirds of the five million headache patients who present to US emergency departments (ED) annually are suffering an acute exacerbation of a primary headache disorder. Of these acute primary headaches, migraine is the most frequently encountered disease entity in the ED, accounting for 60% of primary headaches, followed by tension-type headaches, which represent 10% of all primary headaches seen in the ED. About ¼ of all acute primary headaches seen in the ED cannot readily be given a specific diagnosis3. Multiple parenteral treatments are used to treat acute primary headaches1, but to date, regardless of specific headache diagnosis, no medication eliminates the frequent recurrence of headache after ED discharge. To date, it is unknown which medication patients should be given when discharged from an ED after treatment for a primary headache. This study will compare two oral headache treatments to determine which one relives pain more effectively.